12. It's similar to having an infinite number of solutions because there isn't a specific solution to answer the question.
13. For the equation 0.9x + 5.1x - 7 = 2(2.5x-3), there is only one solution and it is x=1
14. The error that your friend made was that she added extra 16x to the equation. the correct answer is that there is no solution.
16. the equation 6 (x+2)= 5 (x+7) has only one solution. it is x=3.
sorry i wasn't able to answer the other 3,
by the way you don't need to send money, because we are here to help
Answer:
If the shape of end face has n sides
Then, in total, there are n+2 faces
Using that formula
Faces in 20-sided polygon = n+2 = 20+2 = 22
Step-by-step explanation:
Pls vote as brainliest
Let x be the number of months.
The first plan is 15 dollars sign up fee and 38 dollars per month. So the equation is 38x + 15.
The second plan is 78 dollars as sign up fee and 31 dollars per month. So the equation is 31x + 78.
We need find when x has the same value in both equations, so we do their equality:
38x + 15 = 31x + 78
Let's subtract 15 from both sides
38x + 15 = 31x + 78
38x + 15 - 15 = 31x + 78 - 15
38x = 31x + 63
Now let's subtract 31x from both sides to have the variables on a side and the numbers on side:
38x = 31x + 63
38x - 31x = 31x - 31x + 63
7x = 63
Divide both sides by 7 to have the variable x on a side and its value on the other:
(7x)/7 = 63/7
x = 9
So at month 9, the 2 plans will cost the same.
Let's check our answers, and let y be the cost:
y = 38x + 15 = 38*9 + 15 = 357
y = 31x + 78 = 31*9 + 78 = 357
Our answer has been approved.
Hope this helps! :D
Answer:
Step-by-step explanation:
There are two black slices.
So, out of 6 slices, you can land on 2 slices.
2 out of 6
2 / 6
1 / 3
The ratio between the surfaces areas of the two prisms is equal to 6.25.
<h3>
How to get the ratio of the surface areas?</h3>
The ratio between the volumes of the prisms is:
This number is equal to the cube of the scale of dilation applied to the dimensions of the smaller prism, so the scale factor is:
![\sqrt[3]{15.625} = 2.5](https://tex.z-dn.net/?f=%5Csqrt%5B3%5D%7B15.625%7D%20%3D%202.5)
And the ratio between the areas should be the square of the scale factor, then we will have that the ratio between the surface areas of the two prisms is:
If you want to learn more about scale factors, you can read:
brainly.com/question/3457976
